Ninja Strike 4 (Whenever your opponent attacks or blocks, if you have 4 or more cards in your mana zone and you haven't used a Ninja Strike ability this attack, you may summon this Shinobi without cost. At the end of the turn you used this ability put this Shinobi on the bottom of your deck.)When you put this creature into the battle zone, until the start of your next turn, one of your creature's gains "Blocker".